Field of Invention
The present invention relates to power electronics area. More particularly, the present invention relates to a direct-current capacitor module of a power converter and a laminated busbar structure thereof.
Description of Related Art
Electronic products usually require a specific voltage, a specific current or a specific power to be operated properly. Therefore, power converters are needed to transform various power inputs (e.g., power from a household electricity outlet) into signals with appropriate power specifications.
A direct-current (DC) capacitor module (also known as DC-link) is an important part of the power converter. A parasitic inductance of a connective conductor of the direct-current capacitor module is closely related to an over-voltage standard that a power device (e.g., a power switch) of the power converter must withstand. If the parasitic inductance of the connective conductor is reduced, the over-voltage standard withstood by the power device can be reduced, such that a reliability of the power converter is elevated.
The DC capacitor module of a medium-voltage high-power power converter usually consists of a plurality of DC capacitors (with specific electronic specifications) connected in parallel/serial to each others. The DC capacitor module includes several DC capacitors, internal connective conductors (between the DC capacitors), external connective conductors of the DC capacitor module, an insulating layer between aforesaid connective conductors and mounting members for supporting the DC capacitors.
A common way to implement the connective conductors in the DC capacitor module includes placing all DC capacitors on the same plane (all binding posts of the DC capacitors are arranged on the same plane) and utilizing individual connective conductors to connect the binding posts of the DC capacitors separately. The in-flow/out-flow current paths, established by the external connective conductors of the DC capacitor module, occupy a huge loop area. This traditional way is easy to implement the DC capacitors and the connective conductor layout, but the main disadvantage is that the parasitic inductance of the connective conductors will be large. The large parasitic inductance leads the over-voltage on the power device and reduces the reliability of the power converter.
How to reduce the parasitic inductance of the connective conductors, reduce the manufacturing cost, and provide high stability/reliability of the DC capacitor module are important topics in the industry.